SR086/SR087
Adjustable Offline Inductorless Switching Regulators
Features General Description The SR086/SR087 are inductorless switching
regulators designed to operate directly from a rectified
AC line. The operating principle is to turn on a pass
transistor when the rectified AC is below the output
voltage and to turn it off when the output voltage
reaches a specific level. The ICs feature an adjustable
main output voltage of 9V to 50V and an additional
fixed output of 3.3V for SR086 and 5V for SR087.
Efficiencies of around 55% may be realized for loads
up to 1W in 120 VAC applications and about 50%
efficiencies for loads up to 800 mW in 230 VAC
applications. Efficient Operation without Magnetics
No High-voltage Capacitors
Adjustable Main Output Voltage (9V to 50V)
Additional Internal Linear Regulator:
-3.3V for SR086
-5V for SR087
Up to 100 mA Combined Output Current
Single BOM for 120 VAC/230 VAC
Built-in Soft Start
Less than 200 mW Standby Power A logic-level enable input allows the SR086/SR087 to …